rational number(RASH-uh-nuhl NUHM-bur)
Any number that can be written in fractional
form , whereaand bare integers andb0. (p. 72)
ray (RAY) Part of a line that has one endpoint and
continues infinitely in the opposite direction. (p. 240)
real numbers (REEL NUHM-burz) The set of
rational numbers and irrational numbers. (p. 278)
reciprocal (ri-SIP-ruh-kuhl) The multiplicative
inverse of a number.- 1, when a, b0. (pp. 126, 130)
rectangle (REK-tang-guhl) A parallelogram with
four right angles. (p. 260)
rectangular prism (rek-TANG-gyuh-lur
PRIZ-uhm) A polyhedron that has bases that are
rectangles. (p. 302)
rectangular pyramid (rek-TANG-gyuh-lur
PEER-uh-mid) A pyramid that has a rectangular
base. (p. 302)
reduction (ri-DUHK-shuhn) A dilation that is
smaller than the original figure. (p. 374)
reflection (ri-FLEK-shuhn) A transformation that
flips a figure over a line. (p. 370)
reflex angle (REE-fleks ANG-guhl) An angle
whose measure is greater than 180 but less than
360
. (p. 242)
regular polygon (REG-yuh-lur POL-ee-gon)
A polygon with congruent sides and congruent
angles. (p. 252)
regular polyhedron (REG-yuh-lur
pol-ee-HEE-druhn) A polyhedron with faces
that are all congruent. (p. 302)
regular prism (REG-yuh-lur PRIZ-uhm) A prism
with bases that are regular polygons. (p. 302)
relation (ri-LAY-shuhn) A set of ordered pairs that
associates two quantities in a specific order. (p. 358)
relative error (REL-uh-tiv ER-ur) The absolute
error of a measurement in relation to the correct
value (or to the measured value if the correct
value is not known). (p. 273)
relatively prime (REL-uh-tiv-lee PRIME) Two
numbers are relatively prime if their only
common factor is 1. (p. 111)
repeating decimal(ri-PEET-ing DESS-uh-muhl)
A decimal in which a digit or sequence of digits
repeats without end. (p. 72)
replacement set(ri-PLAYSS-muhnt SET) A set of
numbers to be used as possible values for the
variable in an equation or inequality. (p. 56)
representative sample (rep-ri-ZEN-tuh-tiv
SAM-puhl) A sample that has characteristics
similar to the entire population. (p. 208)
rhombus (ROM-buhss) A parallelogram with four
congruent sides. (p. 260)
right angle (RITE ANG-guhl) 1. An angle that
measures 90. (p. 242) 2. The angle opposite the
hypotenuse in a right triangle. (p. 280)
right scalene triangle (RITE skay-LEEN
TRYE-ang-guhl) A triangle with one right angle
and no sides congruent. (p. 254)
right triangle (RITE TRYE-ang-guhl) A triangle
with one right angle. (p. 254)
rotation (roh-TAY-shuhn) A transformation that
turns a figure around a point in either a clockwise
or counterclockwise direction. (p. 372)
rotational symmetry (roh-TAY-shuhn-uhl
SIM-uh-tree) The property of a figure that has a
matching image after being rotated less than a
full turn around a central point. (p. 290)
rotation tessellation (roh-TAY-shuhn
tess-uh-LAY-shuhn) The use of rotated figures to
create a pattern. (p. 292)
S
sale price (SAYL PRISE) The difference between
an item’s list price and the discount. (p. 194)
sales tax (SAYLZ TAKS) The amount of tax
added to the marked price of an item by a state
or local government. (p. 192)
sales tax rate (SAYLZ TAKS RAYT) The ratio of
the amount of sales tax to the marked price
expressed as a percent. (p. 192)
sample (SAM-puhl) A part of a population. (p. 208)
sample space (SAM-puhl SPAYSS) The collection
of all possible outcomes in an experiment. (p. 330)
scale (SKAYL) The ratio of a pictured measure to
the actual measure. (p. 158)
scale drawing (SKAYL DRAW-ing) A two-
dimensional drawing that is in proportion to an
actual object. (p. 158)
scale factor (SKAYL FAK-tur) A scale written as
a ratio in simplest form. (p. 159)
scale model (SKAYL MOD-uhl) A three-
dimensional model that accurately represents a
real object. (p. 159)
scalene triangle (skay-LEEN TRYE-ang-guhl)
A triangle with no congruent sides. (p. 254)a
ba
bb
a434 Glossary